Reinforced thermoplastic composite systems

ABSTRACT

A process is disclosed for the manufacture of reinforced composites. This method provides a process that allows for the direct mixing of discontinuous reinforcement such as wet chopped strands of glass fiber or continuous reinforcement such as glass strands, with an aqueous suspension of a solution polymerized polymer, such as polyvinyl chloride. The process results in a cost-effective means for reinforcing polymers such as PVC while simultaneously substantially improving properties such as impact strength, stiffness, and moldability without the need for a binder.

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION

The present invention relates to a process and method for manufacturingreinforced thermoplastic composites. In particular, the presentinvention provides a process for the manufacture of reinforcedthermoplastic composite compositions such as: (1) Glass MatThermoplastic (GMT) a molding compound containing polyvinylchloride(PVC) resin; (2) reinforced bulk molding compound (BMC) and sheetmolding compound (SMC) containing PVC resin; (3) continuous rovingimpregnated with PVC resin; and (4) other reinforced thermoplasticpolymer composites as per the invention. According to this process, thereinforcing component such as wet chopped strands of glass fiber, glassfiber strands, glass spheres or flakes is directly combined with thecontents of a white water tank containing a suspension of polymerizedpolymer such as PVC. The process may also be carried out by adding thereinforcement to the solution polymerization chamber while the monomerand/or oligomer is polymerizing. This type of process results in acost-effective means for reinforcing polymers such as PVC whileimproving impact strength, heat distortion and stiffness without theneed for added chemical binders. The process can also result in theelimination of a number of manufacturing steps such as centrifugation,filtration, drying and grinding.

BACKGROUND OF THE INVENTION

Chopped glass fibers are commonly used as reinforcement materials inthermoplastic articles. Typically such fibers are formed by drawingmolten glass into filaments through a bushing or orifice plate, applyinga sizing composition containing lubricants, coupling agents andfilm-forming binder resins to the filaments, gathering the filamentsinto strands, chopping the fiber strands into segments of the desiredlength and drying the sizing composition. These chopped strand segmentsare thereafter mixed with a polymerized resin and the mixture suppliedto a compression or injection molding machine to be formed into glassfiber reinforced plastic articles. Typically, the chopped strands aremixed with dried powder of a polymerized thermoplastic resin, and themixture supplied to an extruder wherein the resin is melted, theintegrity of the glass fiber strands is destroyed and the fibers aredispersed throughout the molten resin, and the fiber/resin mixture isformed into pellets. These pellets are then fed to the molding machineand formed into molded articles having a substantially homogeneousdispersion of the glass fibers throughout.

Alternatively, fiber reinforced thermoplastic composites may be formedfrom compression molding of fibrous mats laden with thermoplasticpolymer. Methods of making such fiber reinforced composite materialsfrom an aqueous slurry of solid polymer and reinforcing material areknown. See Published European Patent Applications 0,148,760 and0,148,761, Wessling et al., U.S. Pat. No. 4,426,470 issued Jan. 17, 1984and Gatward et al., U.S. Pat. No. 3,716,449 issued Feb. 13, 1973, all ofwhich are incorporated herein by reference. In general, these reinforcedpolymer composites have a uniform mixture of fiber, polymer and binder,and are prepared from dilute aqueous slurries of a solid heat-fusibleorganic polymer, a reinforcing material and optionally a latex binder.Wessling et al. U.S. Pat. No. 4,426,470 issued Jan. 17, 1984 discloseson column 4, lines 18-21 that various chemical additives such asantioxidants, UV stabilizers, thickeners, foaming agents, antifoamingagents, bactericides, electromagnetic radiation absorption agents, etc.,may also be used in the composites comprising a heat fusible polymer andreinforcing material.

Alternatively, sections of a preformed glass mat, or other shaped glassmat, for example U-shaped channel, or chair seats, may be impregnatedwith a thermoplastic resin powder, and then thermoformed undersufficient heat and pressure to melt the thermoplastic polymer and bondthe glass mat. For PVC impregnated glass mats, the PVC is typically drymixed with a thermal stabilizer and alpha-SAN, and any other additives,to form a homogenous powder prior to impregnation of the glass mat. Ifthe glass mat is to be impregnated with an impact modified blend, theimpact modifier is typically added as a powder and dry-mixed with theother ingredients and does not interfere with formation of the singlephase of PVC and alpha-SAN. Thereafter, the glass mat is then `dusted`or `filled` with the desired amount of the powder mix, generally so thatthere is from about 30% to about 60% mix evenly spread through the mat,and the dusted mat is then molded under pressures of from 100-1000 psiand temperatures of from 170-190° C., to form the shaped glass fiberreinforced PVC blend article.

Glass mat, or other shaped glass fiber stock may also be impregnatedwith a melt of the blend ingredients, such as in pultrusion. Typically,there is about an equal weight of resin and glass fibers in each sheet.Several such sheets may be cut to a predetermined configuration, stackedin a mold and conventionally molded at a temperature of 160-200° C. anda pressure of about 1000 psi (about 30,000 lbf) to form a thick-walledshaped article.

Although there are numerous methods for making reinforced compositemolding materials, many of these processes are either too inefficient,or cannot be sufficiently controlled to produce a fiber reinforcedproduct that provides the resulting composite article with sufficientproperties, such as strength, to meet performance requirements. Thus,even with the current technology of aqueous methods for makingreinforced composite materials, there are numerous drawbacks, includingthe loss of polymer properties as a result of the manufacturing process.Specifically, in the previous technology when using solution polymerssuch as polyvinyl chloride, the vinyl chloride is polymerized, strippedof residual free monomer, the polymer is then processed by somecombination of centrifugation, filteration, and drying. Additives areusually blended at this point. Typically, the dry polymer is combinedwith the reinforcement either by extrusion, dry blending, or aqueousmethods. However, once compounded, the PVC has a significant heathistory since prior to it being combined with reinforcement it hasalready been heated in order to be dried. Then there is the subsequentheating that occurs while being combined with the reinforcement. As aresult, prior to the compound ever being molded to a final product, anumber of important properties have already been reduced by the multipleapplications of heat to the polymer.

Accordingly, a need exists for a more efficient process thatcontrollably yields a fiber reinforced molding compound that providesenhanced performance characteristics to the composite articles moldedtherefrom. Such a process would preferably eliminate the need for binderand improve the heat history of the polymer. This need is fulfilled bythe process of the invention described below.

In addition to the above drawbacks, the current injection moldingtechnology does not have the ability to retain the length of thereinforcement material. In particular, the present technology forcombining reinforcement and polymer results in a compound that has theconsistency of sand, thus obliterating the length of the reinforcement.The invention described below has the ability to retain reinforcementlength. For example, if a 11/4" chopped glass fiber is used, the finalcomposite contains reinforcement essentially of that length. The same istrue for using continuous reinforcement.

SUMMARY OF THE INVENTION

The present invention provides an efficient aqueous process for makingreinforced polymer molding compound and composites. Not only does theprocess eliminate the need for binder as well as a number of processingsteps, but even more significantly, the process dramatically increasesthe available options in terms of molding and performance, compared toprevious methods using equal reinforcement content. Properties such asimpact, flexural and tensile strengths are increased dramaticallycompared to conventionally reinforced molded composites. (See Table 1).The process of the invention provides reinforced molding compoundsranging from granular and sheet to film and continuous. The resultingmats or reinforced molding composite can be used in the manufacture ofarticles as diverse as siding, gutters, and commercial windows.

In general, the invention is primarily directed toward the production ofthermoplastic compounds such as: (1) glass mat thermoplastic (GMT); (2)bulk molding compound (BMC); (3) reinforced polymer films; or (4)impregnated continuous glass strand, roving, yarn, mat or fabric. Oneembodiment of the process allows for the direct mixing of heatstabilized polymer to be directly added, along with reinforcementmaterial, to a white water tank. An additional embodiment utilizes heatstabilized undried polymer which is put into a white water tank and thendirectly mixed with the reinforcement. In another embodiment, theprocess comprises the use of a suspension of solution polymerizedpolymer that may be substantially free of residual monomer.Reinforcement material such as wet chopped glass strands, is thendispersed throughout the polymer suspension. A GMT or BMC is thenprepared as usual without the need for any addition of binder. Inanother embodiment, the reinforcement material is continuous such aswith a continuous glass strand, roving or yarn. The resultingimpregnated complex may be used as input to various secondary processessuch as filament winding, weaving, pultrusion and compression molding.

A further embodiment comprises adding the reinforcement material to thesolution polymerizeable polymer prior to, or simultaneous with, thepolymerization process.

A particular aspect of the process of the invention comprises thefollowing: vinyl chloride monomer is polymerized in an aqueous medium toform an aqueous suspension of polyvinyl chloride; excess free monomer ofvinyl chloride is removed; glass fiber strands comprised of amultiplicity of substantially continuous glass fibers are chopped intosegments of the desired length, the chopped glass fiber strands eitherwet or dry are then dispersed throughout the PVC suspension. Asufficient amount of the aqueous medium is then removed so as to form amoldable composition. In another aspect of the invention, a continuousstrand of glass, carbon or other reinforcement is drawn through theaqueous suspension of PVC or other polymer.

Molded products made according to the invention have comparable orimproved physical properties compared to molded products made fromsystems prepared by previous aqueous and nonaqueous methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of an embodiment of the process ofthe invention. The obvious benefits are simplification of the process bythe removal of a number of steps such as drying of polymer and dryblending. The schematic illustration demonstrates that the processallows for the starting materials such as the reinforcement and polymerto be used at the earliest point so as to lower the cost of materials.It is also clear from the schematic that the resulting compound containspolymer with little or no heat history.

FIG. 2 is a schematic representation of the conventional processpresently used in the art.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS OF THE INVENTION

The present invention provides a process for the manufacture ofreinforced composites. This method allows for the direct and costeffective mixing of reinforcements in any form, such as wet choppedglass, dry chopped glass, continuous glass strand, wet continuous glassstrand or glass flakes into a white water tank containing an aqueoussuspension of solution polymerized polymers such as polyvinyl chloride.As used herein, "white water system" is an aqueous solution in which thereinforcing fibers are dispersed and which can contain numerousdispersants, thickeners, softeners, hardeners, or dispersed oremulsified thermoplastic monomers capable of solution polymerization.Typical examples of various white water systems include aqueoussolutions having acrylamide monomers alone or with hydroxyethylcellulose and the like suspending aids to provide a highly viscousaqueous solution at high material concentrations. Also, white watersystems include those having any of the numerous amine oxide surfactantsas shown in U.S. Pat. No. 4,179,331. In addition to such chemicals asacrylamides or amine oxides being present in the white water system,there can also be present small amounts of surfactants such aspolyethoxylated derivatives of amide condensation products of fattyacids and polyethylene polyamines as is shown in U.S. Pat. No.4,265,704. Also numerous other chemical agents can be added to a whitewater system as is known by those skilled in the art.

Reinforcement useful in the invention include dispersible materials ,non-dispersible materials and combinations of the two forms. Preferreddispersible reinforcements include materials such as wet chopped strandsof glass, aramides, carbon, polyvinyl alcohol (PVA), hemp, jute, organicmaterials, mineral fibers and rayon. Preferred non-dispersiblereinforcement materials include dry chopped strands and glass fibersdesigned for processes such as SMC molding, BMC molding and continuouspanel fabrication; chopped and continuous reinforcements such asaramide, carbon, glass, wollastonite, jute; mica, flake glass, glass andcarbon spheres, mats, organic materials, mineral fibers, and fabrics.

The preferred reinforcement materials include organic and inorganicmaterials such as graphite, metal fibers, aromatic polyamides, celluloseand polyolefin fibers, but preferably and advantageously comprises glassfibers such as wet chopped glass strands having a length of about 1/8 to2.0 inch (about 3.2 to about 50.8 mm), milled glass fibers whichgenerally have a length of about 1/32 to 1/8 inch (about 0.79 to 3.2 mm)and mixtures thereof. The preferred type of reinforcement is glass fiberin any of its commercially produced compositions. The fibers arepreferably surface treated with chemical sizing or coupling agents whichare well known in the art. Preferred sizings are selected so as to aidin dispersion without negatively affecting properties in the dispersedreinforcement systems. The preferred sizings for nondispersedreinforcement systems are selected to minimize dispersion. The preferredsizing should be compatible with the polymer of choice such thatproperties are optimized. The most preferred continuous glass strand orchopped glass fiber reinforcement is used wet.

A preferred fiber reinforcement is wet chopped glass obtained from OwensCorning. Similarly the fiber reinforcement may be used in the form of acontinuous glass strand. For example, glass strands such as TYPE 30®roving obtained from Owens Corning may be used. Preferably, the glassstrand or chopped glass fibers is used wet and added to the solutionpolymerized polymer. Typical water content for wet chopped strandsranges from about 10% to about 25%. For continuous roving it ranges fromabout 2% to about 15%.

The reinforcing material generally comprises from about 10 to about 80weight percent of a composite when using chopped material. When usingcontinuous reinforcement material the weight percent of reinforcementgenerally comprises from about 30 to about 80 weight percent of thecomposite. In applications where a rigid molded part is desired thereinforcing material generally comprises from about 10 to about 80weight percent of the composite. Whereas in applications such as filmswhere minimum stability is required from the reinforcing material itgenerally comprises from about 10 to about 50 percent of the composite.In a preferred embodiment it comprises from about 20% to about 40% of acomposite using chopped material. When using continuous reinforcement toproduce a prepreg, the prepreg will generally contain about 20% to about60% polymer by weight. In a more preferred embodiment it will containabout 25% to about 45%. When using noncontinuous reinforcement thecomposite will generally contain about 50 to about 90 percent polymer byweight. In a more preferred embodiment it will contain about 60 to about80 percent.

Aqueous suspensions of polymers useful in the invention, includesuspensions wherein the polymer particle size ranges from about 10microns to about 500 microns. In a more preferred embodiment, theaverage particle size ranges from about 30 microns to about 200 microns.The polymer particle size used will typically be larger or on the sameorder as the filament diameter of the reinforcement material.

One of the direct processes of the invention for producing a reinforcedpolymer composite or mat involves forming an aqueous suspension ofdiscontinuous fibers like wet chopped glass fibers and an aqueoussuspension of a thermoplastic polymer usually with agitation in a mixingtank. The resulting combined aqueous suspension, usually referred to asslush or pulping medium, may be processed into a wet-laid, sheet-likematerial by such machines as cylinder or Fourdinier machines or othertechnologically advanced machinery, such as the Stevens Former, RotoFormer, Inver Former and the VertiFormer machines. The slush isdeposited from a head box onto a moving wire screen or onto the surfaceof a moving wire-covered cylinder. The slurry on the screen or cylinderis processed into the nonwoven, sheet-like mat by the removal of water,usually by a suction and/or vacuum device. This process is exemplifiedin U.S. Pat. No. 5,393,379.

The sheet-forming and dewatering process may be accomplished by anyconventional paper making apparatus such as a sheet mold or aFourdrinier or cylinder machines. After the mat is formed into adewatered sheet, it may be desirable to densify the sheet by pressing itwith a flat press or by sending it through calendering rolls.Densification after drying of the mat is particularly useful forincreasing the tensile and tear strength of the mat. Drying of the matmay be either air drying at ambient temperatures or oven drying.

The process of the invention provides for the direct formation ofmolding compound containing from about 10% to about 80% reinforcingmaterial. Preferably, the process provides for molding compound havingfrom about 20% resin to about 90% resin.

In the process, a dilute aqueous suspension is prepared containing themonomer particulates to be polymerized. The suspension solution willalso contain the necessary initiator. In addition, depending upon thesolution polymerizable polymer used, a heat stabilizer may also beadded. For polymers using a heat stabilizer, it may be added at the timeof polymerization, when the reinforcement material is added, or anyother convenient time during the process. The solution of monomer isthen allowed to polymerize. If desired, after polymerization any freeexcess monomer is removed or stripped from the polymer solution. Thisstep may be avoided by starting with previously polymerized materialthat is wet or dry.

The preferred polymer of the invention is solution polymerizeable.Solution polymerizeable polymers such as polyvinylchloride (PVC),acrylonitrile-butadiene-styrene (ABS), and polypropylene (PP) are amongthe preferred. Additionally, suitable polymers include addition andcondensation polymers such as, for example, the polyolefins,polystyrenes, phenolics, epoxies, butadienes, acrylonitriles, andacrylics. In addition the preferred polymer will be "heat fusible." By"heat fusible" is meant that the polymer particles are capable ofdeformation under heat to join into a unitary structure. The heatfusible polymers may be either thermoplastic or thermoset resins. Theheat fusible organic polymer component of the present invention isdesirably a hydrophobic, water insoluble polymer.

The solution polymerized polymers generally, and are advantageously,either PVC, ABS or PP. The polymers are generally employed in an amountfrom about 20 to about 90 percent by weight of the solids (dry weightbasis of the combined weight of fibers and formulated resins). Aparticularly preferred organic polymer is a polyvinyl chloride resinthat already contains a heat stabilizer. Polymer blends may be used aswell. Whether one polymer is used or a blend, the preferred initiatorwill be selected for the particular monomer or blend of monomers in use.

In another process of the invention, a strand of substantiallycontinuous glass fibers is formed by conventional techniques such asdrawing molten glass through a heated bushing to form a multitude ofsubstantially continuous glass fibers and collecting the fibers into astrand. Any apparatus known in the art of producing such fibers andcollecting them into a strand can suitably be used in the presentinvention. Suitable fibers are fibers having a diameter of from about 3to about 90 microns, and suitable strands may contain from about 50 toabout 4000 fibers. Preferably, the strands formed in the process of theinvention contain from about 200 to about 2000 fibers having a diameterof from about 3 to about 25 microns.

After the fibers are formed, and prior to their collection into astrand, the fibers are coated with the sizing of the invention.Preferably the sizing composition is selected so as to aid in thedispersion of the reinforcement in the white water solution ofpolymerized polymer. For example, a preferred sizing for a continuousglass roving reinforcement will allow for use of a wet roving i.e.having about 2 to about 15% by weight water. The sizings are preferablywater-based and comprise one or more silanes, film-formers, surfactants,etc. An example, of such sizing would be Owens-Corning's wet choppedfiber with a sizing designated 9501. When using PVC in a embodiment thepreferred sizing contains an amino silane such as A1126, A1125, A1120,A1102, and A1100 obtainable from union carbide.

As one of ordinary skill in the art knows, the final material may be UVstabilized or not depending on the needs and use of the composite. Inaddition, the material may contain any number of other additives, suchas colorings, necessary to meet the functional performance of theapplication.

EXAMPLE I Preparation of GMT from Wet Chopped Glass Fiber

A randomly oriented, 1-inch glass fiber/PVC sheet was successfullyformed on a wet process mat line by mixing heat stabilized PVC powderdirectly with wet chopped glass strands obtained from Owens Corning in awhite water tank. No additional chemical binder was added or needed.Process limits in terms of sheet weight and maximum drying temperaturesfor various line speeds were determined as is usual in the art. The PVCpowder could be sintered to the glass at 25 ft/min with little, if any,resin degradation. The resulting mats contained 80% PVC resin (byweight) and 20% fully dispersed E-type glass fibers.

The mats were successfully molded into panels. The actual molding of thecomposite panel was preformed by stacking several sheets of the in-linedried mat (no more than 1% water retention), molding in a heated press,and then cooling under pressure. The physical properties of the panelsobtained from such mats may be found in Table 1 shown below. Table 1compares the properties of panels molded from composite glass fiber matsmade via the inventive process (designated Direct Process) to moldedpanels made without reinforcement (designated Unreinforced) and moldedpanels made from the current technology (designated Prior Technology).The prior technology utilizes PVC and glass pellets; which were useddirectly in injection molding. As shown in Table 1, not only are theproperties of the panels molded from the glass mats of the inventioncomparable to those of the prior technology, but for a number ofproperties they are significantly superior.

                  TABLE 1                                                         ______________________________________                                        Designated  Direct Process                                                                           Unreinforced                                                                            Prior Technology                             ______________________________________                                        Polymer Type                                                                              PVC        PVC       PVC                                          Glass Form  Wet Chopped                                                                              None      Dry Chopped                                              Strands              Strands                                      Glass Fiber Input                                                                         25 mm      --        4 mm                                         Length                                                                        Glass Content                                                                             20%        0%        20%                                          by weight                                                                     ______________________________________                                        MECHANICAL                                                                    Tensile Strength (ksi)                                                                    15         6.3       14                                           Tensile Elongation (%)                                                                    2.5        35        2                                            Tensile Modulus (Msi)                                                                     1          0.35      1.1                                          Flexural Strength (ksi)                                                                   26         10.3      22                                           Flexural Modulus                                                                          1.2        0.36      1                                            (Msi)                                                                         Izod Ipact Strength,                                                                      4          7.4       1.6                                          Notched (ft-lbs/in)                                                           Izod Impact Strength,                                                                     6          --        6.5                                          Unnotched (ft-lbs/in)                                                         THERMAL                                                                       Coefficient of Thermal                                                                    1.6 × 10.sup.-5                                                                    4 × 10.sup.-5                                                                     1.2 × 10.sup.-5                        Expansion (in/in-° F.)                                                 PHYSICAL                                                                      Specific Gravity                                                                          1.53       1.33      1.53                                         (g/cm.sup.3)                                                                  Glass Fiber Content                                                                       20         0         20                                           (% by weight)                                                                 ______________________________________                                    

EXAMPLE II Preparation of a Composite Mat from Wet Chopped Glass Fiberand Non-Dispersed E-type Glass

As with Example 1, PVC GMT sheets were formed. Glass/PVC composite matswere formed with two different ratios of dispersed (wet chopped strand)to non-dispersed (973 SMC Roving, obtained from Owens-Corning) glass inthem. The ratios were 1:2 and 2:1. Both ratios resulted in successfulformation of the composite mats.

EXAMPLE III Preparation of a Continuous Reinforced System

The actual production involved making a suspension of PVC as inExample 1. The continuous glass roving was then pulled through thesuspension of PVC. The continuous glass roving used was a TYPE 30®(obtained from Owens-Corning) roving that was not dried i.e. containing14% water by weight and contained a sizing designed for use in wetprocesses.

What is claimed is:
 1. A process for the preparation of a reinforcedcomposite comprising:a) preparing an aqueous suspension of solutionpolymerizable polymer; b) adding reinforcement material directly to saidaqueous polymer suspension during or after the polymerization process;and c) removing a sufficient amount of said aqueous medium from saidsuspension to form a moldable composition.
 2. The process of claim 1,wherein said aqueous suspension of polymer is prepared from the groupconsisting of dry polymer, wet polymer, or solution polymerizablemonomer.
 3. The process of claim 1, wherein said reinforcement materialis added wet.
 4. The process of claim 1, wherein said reinforcementmaterial is added dry.
 5. The process of claim 1, wherein saidreinforcement material is continuous.
 6. The process of claim 1, whereinsaid reinforcement material is discontinuous.
 7. The process of claim 1,wherein said reinforcement material is selected from the groupcomprising: dispersible, nondispersible, or combinations of the twoforms.
 8. The process of claim 7, wherein said dispersible reinforcementis selected from the group comprising: wet chopped strands, aramides,carbon, polyvinyl alcohol, hemp, jute, organic materials, mineral fibersand rayon.
 9. The process of claim 7, wherein said non-dispersiblereinforcement is selected from the group comprising: dry used choppedglass strands; glass fibers designed for processes such as SMC molding,BMC molding and continuous panel fabrication; chopped and continuousreinforcements such as aramide, carbon, glass, wollastonite, and jute;mica, flake glass, glass and carbon spheres, mats, mineral fibers,organic materials and fabrics.
 10. The process of claim 8, wherein saidwet chopped glass strands have a length of about 3.2 mm to about 50.8mm.
 11. A process for the preparation of a reinforced composite thatsubstantially retains the length of the added reinforcement materialcomprising:a) preparing an aqueous suspension of solution polymerizablepolymer; b) adding reinforcement material directly to said aqueouspolymer suspension during or after the polymerization process; and c)removing a sufficient amount of said aqueous medium from said suspensionto form a moldable composition.
 12. A process for the preparation of areinforced composite that substantially improves the heat history of thepolymer in the resulting composite comprising:a) preparing an aqueoussuspension of solution polymerizable polymer; b) adding reinforcementmaterial directly to said aqueous polymer suspension during or after thepolymerization process; and c) removing a sufficient amount of saidaqueous medium from said suspension to form a moldable composition. 13.A process for the preparation of glass fiber reinforced polyvinylchloride composite comprising:a) preparing an aqueous suspension ofpolyvinyl chloride; b) dispersing wet chopped glass strands throughoutsaid polyvinyl chloride suspension; and c) removing a sufficient amountof said aqueous medium from said suspension to form a moldablecomposition.
 14. A process for the preparation of glass fiber reinforcedpolyvinyl chloride composite comprising:a) forming a woven or nonwovencomplex of reinforcement fibers; b) preparing an aqueous suspension ofpolyvinyl chloride; c) impregnating said polyvinyl chloride suspensionthroughout said reinforced complex; and d) drying said reinforcedcomplex to form a moldable article.
 15. A process for the preparation ofglass fiber reinforced polyvinyl chloride composite comprising:a)preparing an aqueous suspension of polyvinyl chloride; b) preparing aglass fiber strand comprised of a multiplicity of substantiallycontinuous fibers; c) impregnating said fiber strand with said polyvinylchloride suspension; and removing a sufficient amount of said aqueousmedium to form a moldable composition.
 16. A process for the preparationof reinforced composite comprising:a) forming a woven or nonwovencomplex of reinforcement fibers; b) preparing an aqueous suspension ofsolution polymerized polymer; c) impregnating said aqueous suspensionthroughout said reinforced complex; and d) drying said reinforcedcomplex to form a moldable article.
 17. A process for the preparation ofreinforced composite comprising:a) preparing an aqueous suspension ofsolution polymerized polymer; b) preparing a fiber strand comprised of amultiplicity of substantially continuous fibers; c) impregnating saidfiber strand with said aqueous suspension; and d) removing a sufficientamount of said aqueous medium to form a moldable composition.
 18. Theprocess of claim 16, wherein said reinforcement fiber is selected fromthe group comprising one or more of the following: mat, veil, continuousfibers, woven fibers, chopped strand mat, continuous filament mat,knitted mat or fabric or needle punch fabric.
 19. A process for thepreparation of a reinforced mat composite comprising:a) preparing anaqueous suspension of solution polymerizable polymer; b) addingreinforcement material directly to said aqueous polymer suspension; c)transferring said reinforcement and polymer mixture to a mat machine; d)drying said reinforced mat; and e) sintering the organic material ontosaid reinforcement if necessary for the specific polymer used.